[New information concerning pain caused by herniated disk and sciatica. Exposure to disk tissue sensitizes the nerve roots].

Sciatica has long been considered to be solely due to mechanical deformation (compression) of a spinal nerve root by herniating disc tissue. However, recent experimental findings have demonstrated that, even in the absence of mechanical insult, nucleus pulposus-related substances may not only induce significant structural and functional injury to the adjacent nerve root, but also sensitise the nerve root, producing pain in the event of subsequent root compression. Although neither the specific mechanisms nor the active nucleus pulposus-related substances causing pain have yet been identified, the recent findings suggest that the future may well bring new pharmacological treatment alternatives for sciatica and disc herniation.